Monoclonal antibodies for therapeutic cancer treatment undergo a costly and time-consuming evaluation procedure. Usually they are derived by e.g. immunization with the respective tumor antigen or fragments thereof, which yields hybridomas producing monoclonal antibody against the tumor antigen. Before further intensive evaluation a time-consuming purification procedure has to be performed after which they are evaluated first in vitro, and then in preclinical animal studies. In the in vitro studies mainly their binding affinity to the respective tumor antigen and the growth inhibition on human tumor cells is determined, which is a prerequisite for preclinical animal testings. However, it has been shown, that the in vitro tumor cell growth inhibition does not always correlate with the efficacy in the in vivo xenograft animal studies. It has been shown, that antibodies which have good antiproliferative activity in vitro, can be totally inactive in the preclinical in vivo model, while in vitro inactive antibodies can execute significant in vivo efficacy. Therefore, in general the preclinical animal testings for such antibodies is extensive and time consuming, and a lot of different antibodies have to be tested because of the poor predictive potential of the in vitro studies. A reduction of preclinical animal testing and also a less time-consuming procedures is therefore one important task in the development of monoclonal antibody against the tumor diseases.
Staquet and Giles-Komar (Hybridoma 2006; 25: 68-74) describe a method of the in vivo evaluation of monoclonal antibodies. They injected hybridomas in matrigel subcutaneously into mice. Four days later, tumor cells were injected subcutaneously into the same mice, and the tumor growth was measured over time. A reduced tumor growth or no tumor growth in comparison with control hybridomas indicated the antiproliferative efficacy of the monoclonal antibodies produced by the respective hybridomas. With this method it is possible to distinguish anti-tumor active antibodies from non-anti-tumor active antibodies. However, this method allows no or only poor differentiating possibilities between the antiproliferative potential of antibodies, which still have to be purified from the hybridomas and tested again for further evaluation of their antiproliferative potential.